Originally Posted by
ebra
Is that correct?
Most probably, yes.
Originally Posted by
ebra
If so, how do I avoid ending up in the same mess again?
By not booking cross *A codeshares unless you absolutely have to.
Originally Posted by
ebra
And is the rule published anywhere on any SK site?
No, it's not.
This is the biggest problem of *A in general regarding code share flights (certainly both EB and M&M suffer from the same problem): code share flights are credited as if they were flown by the operating carrier, not by the ticketed/marketing carrier. That wouldn't be so bad if the booking classes were directly aligned (i.e. SK V = UA V), but as you just witnessed, they are not. SK V on an UA metal maps to a lower fare bucket, which turns out to be 25% mileage earning. To add insult to injury, this mapping information is not public, and it looks like even SK agents (and EB staff) do not know it and cannot access it. The only way is trial and error - I'm sure you won't be booking any V class SK on UA flights any more..
Unfortunately there's no easy way out of it, apart from avoiding code shares in the first place.
I wish they would do it like they do on OW - an AA flight in V is credited as an AA flight in V, no matter whether it is on actual AA metal, an AS (i.e. non-OW) code share or an BA codeshare (i.e. OW).